JP4709453B2 - Threaded pipe connector that can withstand external pressure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a threaded connector for pipes particularly important for tight seals that can withstand high pressures from the outside, especially steel pipes suitable for the gasoline and gas industry, and pipes connected to this connector The present invention relates to a screw connector.
[0002]
[Prior art]
Pipe connectors used in the gasoline and gas industry are known and are constituted by male elements threaded on the outside and screwed on female elements threaded on the inside. Such connectors are used to construct continuous extraction pipes or steel pipes for gasoline and gas wells.
[0003]
Depending on the severity of the conditions for wells for gasoline and gas development, the basic structure of the above-mentioned connector, as is well known, uses various types of sealing members such as synthetic materials or metal surface rings that press against each other. It has been completed by providing those connectors.
[0004]
An example that may be cited is disclosed in EP 0488912. It is tapered with a male tapered surface in the area behind the male thread near the free end of the male element and a corresponding female tapered surface in the corresponding area of the female element. A connector is disclosed. The pair of male and female surfaces press against each other when their connectors are arranged to form a surface that seals from the inside against the fluid circulating in the pipe. The connector disclosed in EP 0 488 912 is also provided with an abutment that, when assembled, allows the two male and female threaded elements to be placed in precise positions relative to each other.
[0005]
For some applications, the connector must resist and seal against the pressure of the internal fluid circulating in the pipe and the external pressure present outside the pipe. Such seals are reliable for connectors when the external pressure is high (eg above 600 bar), regardless of whether the fluid concerned is liquid or gas or a mixture of the two. It will be important to ensure. For such applications, when a predetermined pressure is exceeded, the inner sealing surface as disclosed in EP 0488912 cannot resist the penetration of fluid traveling from outside to inside along the screw, Later, the male lip provided with its inner sealing surface may deform or even break, resulting in fluid permeation inside the pipe.
[0006]
In order to overcome this problem, it has been proposed to provide a connector of the type disclosed in EP 0488912, in which a sealing surface is arranged near the free end of the female element.
[0007]
FR7712851 discloses a connector comprising an inner sealing surface near the free end of the male element and an outer sealing surface near the free end of the female element. It must be able to withstand internal and external pressures. However, according to FR7712851, each of those two sealing surfaces is coupled to an abutment, making it more difficult to perform the function of the connector and to manufacture it. Abnormal deformations can occur if the overall dimensions are not acceptable or if the assembly torque is excessive, which fundamentally changes the function of the two sealing surfaces and further Loss of tightness with respect to the fluid inside and the fluid outside the pipe.
[0008]
Manufacturing such a connector is expensive. It firstly requires machining tolerances in order for it to function properly, and secondly, to use thick pipes, it produces both inner and outer sealing surfaces. This is because such a material is required for the purpose.
[0009]
The prior art described above also provides two radially and axially offset independent threaded regions where the male and female elements have sealing surfaces (such threaded regions may be referred to as steps). Also disclosed is a connector consisting of a tapered or straight tube constructed by:
[0010]
It is the case of EP767335, which has two separate radial and axially offset thread areas, Thereby, their threaded regions arranged on two separate cones are axially offset from each other, A connector consisting of a tapered tube is disclosed having an inner sealing surface near the free end of the male element and an outer sealing surface near the free end of the female element. However, because the outer sealing surface is close to the free end of the female element and there is not enough material at the end of the pipe to hold the surface firmly, the outer sealing surface is very high pressure I can't fight.
[0011]
In addition, EP 0149612 has two threaded areas offset in two radial and axial directions. That is, their threaded regions located on two separate cones are offset axially from each other A connector composed of a tube is disclosed. Between those areas Has a sealing surface. These areas are also constituted by male and female surfaces that are in bearing contact during assembly. The connector also consists of an inner sealing surface near the free end of the male element and a diagonal abutment at the free end of the female element.
[0012]
Due to the structure of the two threaded regions offset in two radial and axial directions, the connector of EP 0149612 requires a relatively thick pipe wall and, furthermore, due to the corresponding cost and volume it is coupled It is difficult to envisage manufacturing with.
[0013]
[Problems to be solved by the invention]
The present invention provides a threaded pipe connector that firmly resists external pressure and does not have the disadvantages of the connector described above.
[0014]
In other words, it can withstand external high pressures against the internal pressure, has a simple structure, is robust, and is more economical in terms of required pipe thickness and material quality and machining. A connector is sought.
[0015]
The term “robust” means a connector that can withstand high pressures, for example on the order of 600 bar to 1500 bar, which can be easily assembled in the field.
[0016]
There is also a need to manufacture threaded pipe connectors. The connector is hardly different from existing connectors and consists of two separate radial and axially offset threaded areas, Thereby, their threaded regions arranged on two separate cones are axially offset from each other. Unlike a threaded connector, it is constituted by a single threaded region, and it can be manufactured from a connector having a single threaded region without changing the structure of the assembly.
[0017]
There is also a need for a connector with a single sealing means that can be used to counter both internal and external pressures.
[0018]
The connector of the present invention is suitable for manufacturing pipelines or strings.
[0019]
The field of application is not limited to the gasoline and gas industry, but extends to any application where similar problems may or may occur.
[0020]
Non-limiting examples include geothermal fluid or water vapor extraction.
[0021]
The connector is manufactured from any metallic material that has the desired mechanical properties and also has the required corrosion strength for the expected application, including for example steel or ferrous or non-ferrous alloys it can.
[0022]
[Means for Solving the Problems]
The threaded pipe connector of the present invention is of the type consisting of a male element disposed at the end of the first pipe and a female element disposed at the end of the second pipe.
[0023]
The male element consists of an external male thread composed of a single male threaded area, and the female element consists of an internal thread composed of a single female threaded area, the male threaded area Corresponds to the female threaded region, so that they can be incorporated one into the other.
[0024]
The male and female threads are tapered, and the stop means can stop the assembly of the connector at the set position.
[0025]
A sealing member is inserted between the male element and the female element. The sealing member is composed of a male bearing surface on the male element and a female bearing surface on the female element, the two bearing surfaces having bearing contact with each other when the connector is assembled. Furthermore, each is located in a generally central area of the male threaded area for the male bearing surface and in a generally central area of the female threaded area for the female bearing surface. The male and female screws are interrupted at the bearing surface.
[0026]
The term “generally central area” of the male and female threaded areas where the male and female threads are interrupted is along the connector axis of the male and female threaded areas. Either a region in the approximate center position or a central position along the connector axis of the male and female threaded regions up to a length of up to 1/4 of the length along the connector axis of the threaded region It means the area in the part extending to the side.
[0027]
Advantageously, the male and female threaded regions are considered to enclose both complete screws and incomplete, extinguished or defective end screws.
[0028]
In the following description, this sealing means is simply referred to as “central sealing means”. This term is Regarding the definition of the overall central region above It should not be interpreted in a limited way in view of the information.
[0029]
The stop means that can stop assembling the male element in the set position of the female element can be assembled by means that couple directly to the screw or by means other than the screw.
[0030]
Since the screw is tapered, the screw will naturally have an interference fit, and the stop means directly coupled to the screw may be assembled to a predetermined torque, as is known, or Can be assembled with two marks, one on the male element and one on the female element, which coincide at the end of the.
[0031]
With respect to the means independent of the screw, the stop means can be an abutment that prevents continuous relative assembly of the male element to the female element.
[0032]
According to the anticipated service relating to the connector of the present invention, the connector consists of only a single sealing means and a central sealing means, as described above, or may include a second sealing means in addition to the central sealing.
[0033]
The second sealing means is a means known per se, such as a metal-to-metal bearing contact guaranteed by two bearing surfaces, each of which is one of the free ends of the male element And the other is located in the corresponding part of the female element.
[0034]
The bearing surfaces of the central seal means may be of any type or shape as long as they can make bearing contact with each other during assembly of the connector.
[0035]
For example, use two cylindrical surfaces to make the male bearing surface slightly larger in diameter than the female bearing surface, thereby ensuring an interference fit between the two surfaces when forming the assembly seal can do.
[0036]
At least one cylindrical surface can be used and the other surface can be, for example, an annular surface, or of a type that can be interference fitted with the former.
[0037]
The male bearing surface and the female bearing surface need not have the same structure.
[0038]
Advantageously, at least one of the bearing surfaces of the central sealing means, the male surface or the female surface is constituted by a tapered surface, the taper being in the same direction as the taper of the screw, but advantageously In addition, the angle of the male and female elements relative to the common axis is greater than the angle of the taper of the screw relative to that axis.
[0039]
By way of non-limiting example, the contact distance between the male and female bearing surfaces of the central seal means is in the range of 1 to 10 mm.
[0040]
The male and female element screws can be, for example, triangular or trapezoidal API (American Petroleum Institute) screws, the latter being referred to by the API as the world-known name “buttress”, whose use is It is common for those who design seed screws.
[0041]
In the case of buttress screws (or sawtooth screws), they allow the screws to better engage each other by having opposite flank, especially when mating with an abutment Can do.
[0042]
The present invention also relates to a threaded connector for two pipes using the connector of the present invention, the structure of which is as described above.
[0043]
Many variations are possible.
[0044]
In the first modification, the coupling is integral, and as described above, each pipe to be coupled alternately holds the male and female elements of the connector of the present invention at each end thereof.
[0045]
Thus, the integral joining of the two pipes is performed by screwing the male element at the end of the first pipe into the female element at the end of the second pipe.
[0046]
Depending on the shape and thickness of the pipe, it is convenient to form a female element at the end of the pipe whose outer diameter is pre-expanded, the male element being formed on the pipe, the end of which is If necessary, the thickness is increased by, for example, hot forming.
[0047]
In the second variant, the coupling for the two pipes is performed using a coupled type, i.e., a coupling that couples the two pipes, and utilizes the two connectors of the present invention. Its structure is as described above.
[0048]
In that case, the male element is formed at the end of each pipe, and the female element is formed at each end of the coupling and is at the two ends of the two pipes to be joined. The two male elements are screwed into the two female elements of the coupling.
[0049]
In that case, in the first embodiment, the free ends of the two pipes to be joined can be in bearing relation to each other inside the coupling at the completion of the assembly, so that the assembly can be stopped in the set position. A possible abutment is constructed.
[0050]
In the coupled second embodiment, the free end of each pipe forms a bearing relationship with a stop lug provided in the central portion of the coupling.
[0051]
The accompanying drawings and description of the embodiments do not limit the connector and coupling examples of the present invention.
[0052]
DETAILED DESCRIPTION OF THE INVENTION
In order to better represent the present invention, the accompanying drawings are intentionally simplified, and dimensions, angles and ratios of dimensions are not necessarily taken into account. Some dimensions are exaggerated considerably.
[0053]
1 and 2 are partial axial cross-sectional views along a plane passing through the common axis X1-X1 of the male element 1 and the female element 2, and these elements are the elements of the threaded connector 5 of the present invention. It is arrange | positioned at the edge part of the 1 steel pipe 3 and the 2nd steel pipe 4, respectively.
[0054]
Their male element 1, Female element 2 is shown in FIG. 2 in a coupled state, i.e. with the connector 5 in the assembly position. FIG. 1 shows the state before assembly.
[0055]
In order to better show the connector before being joined, the female element 2 is radially offset from its axis X1-X1 in FIG.
[0056]
The outer diameter of the end 6 of the pipe 4 in which the female element 2 is formed is larger than the diameter of the continuous part 4 of the pipe, and the diameter in the part 6 is obtained by enlarging the end of the pipe. It is made.
[0057]
The male element 1 consists of an external male screw constituted by a male screw region Fm. The screw 7 is tapered and outlined as indicated conventionally by the two tangents of the screw with respect to the thread and valley bottom.
[0058]
The screw 7 is made on a single taper, and the screw has a known shape and is of the type appropriate for the desired application for the connector and the service requirements.
[0059]
Screws consisting of two radially and axially offset separate screw regions (or steps in which two screws are formed) on each male and female element, such as the connector disclosed in EP 0767335 In contrast to the attached connector, the connector of the present invention is formed like a connector having a screw constituted by a single screw region.
[0060]
Therefore, the region Fm in which the male screw is formed is considered to be a single male screw region, and its length Lm corresponds to the axial length of the screw from one end to the other end, The length includes incomplete, vanished or insufficient screws at the ends.
[0061]
The female element 2 has a tapered inner female threaded part 8 corresponding to the male threaded part 7 and is constituted by a single female threaded region Ff which is shown to be similar to the threaded part 7. Yes.
[0062]
It consists of a single threaded area, whose length Ff ranges from the axial length of the thread from one end to the other, the length being incomplete at those ends, Includes dead or inadequate screws.
[0063]
The central sealing means 9 is placed between the male element 1 and the female element 2 of the threaded portions 7, 8.
[0064]
The means 9 is composed of a male bearing surface 10 and a female bearing surface 11, which are arranged in the center of the male screw region Fm and the female screw region Ff, respectively, in which the respective male screw part and The internal thread portion is interrupted, and the two bearing contacts 10 and 11 can be in contact with each other in the coupled state of the connector, as shown at 9 in FIG.
[0065]
Thus, the pressure of the metal-to-metal contact between faces 10 and 11 forms a continuous annular face-shaped seal that prevents fluid penetration from the outside of the pipe to the inside or vice versa. .
[0066]
“The overall central region of the male screw region Fm and the female screw region Ff” is a region provided at a central position along the lengths Lm and Lf, or 1/4 of the lengths Lm and Lf of the screw portions. It means a region extending on both sides of the center position of the lengths Lm and Lf by an equal length. Note that the position is selected as a function of the pressure from the outside of the fluid to be tolerated and the thickness of the pipe.
[0067]
In order for the surfaces 10 and 11 to coincide completely at the end of assembly, the connector of the present invention has stop means that can stop assembly at a set position in the relative axial direction of the male element 1 relative to the female element 2. Prepare. In the case of FIGS. 1 and 2, such a stop means is constituted in a known manner by two marks 12, 13 shown as thick lines on the male element 12 and the female element 13. The assembly of elements 1 and 2 can be stopped when their marks 12 and 13 coincide, as shown in FIG.
[0068]
The marks 12 and 13 have a predetermined interference fit between the male screw portion 7 and the female screw portion 8 due to the taper shape of the screw that can form a screw interference fit between the male screw portion 7 and the female screw portion 8. Is positioned to form.
[0069]
The “fitting fit” is a positive that exists before assembly at the level of the regions Lm and Lf between the radius with respect to the connector axis at the position on the male thread region 7 and the radius at the corresponding position on the female thread region after assembly. Mean difference.
[0070]
Advantageously, the interference fit measured between the bearing surfaces 10, 11 with respect to the connector axis is at least as large as, or desirably greater than, the interference that exists between the threads 7, 8. The assembly path of the bearing surface to the coupled position is shortened.
[0071]
The threaded portions of both the male threaded area Fm and the female threaded area Ff on both sides of the central sealing means 9 can be assembled and removed without difficulty, for example, as shown in FIGS. Has been interrupted.
[0072]
The seal obtained by the central sealing means 9 as described above is particularly effective for high pressure from the outside. That is because the generally central male and female bearing surfaces 10, 11 are held by a metal of sufficient thickness with respect to the pipe thickness in both male element 1 and female element 2. It is.
[0073]
Advantageously, attention is paid at least for service conditions, with respect to the male element 1 the thickness of the member at the level of the male bearing surface is at least 50% of the thickness of the pipe 3. ing.
[0074]
Satisfying such a condition is impossible, for example, when the sealing surface of the connector is provided beyond the thread at the end of the male element, as in EP 0488912.
[0075]
Increasing the thickness at the level of the bearing for the male element creates problems. It requires the connector to have a very small taper, thereby creating difficulties with engaging the male element with the female element, and also requires a very large diameter and length, As a result, the female element becomes very expensive.
[0076]
The connector of the present invention can be made from a conventional tapered thread with a single threaded region.
[0077]
That is, a much thinner pipe is required than a conventional connector consisting of two separate axially and radially offset threads or steps. Therefore, the connector of the present invention is very compact, inexpensive in terms of materials, and easy to machine.
[0078]
Furthermore, because of the generally central part of the central sealing means 9, the male thread region can extend to the end 14 of the male core with a complete thread, from which the efficiency of the female element 2 can be extended. Is calculated.
[0079]
Thus, the volume of the connector can be reduced with respect to the female element. That is, the outer diameter of the female element 2 can be reduced compared to a conventional connector having a sealing surface at the end of the male element.
[0080]
Similarly, the internal thread portion 8 can be extended towards the free end of the female element until a suitable outer diameter of the pipe 3 is obtained. Therefore, the efficiency of the connector is 100% of that of the pipe 3. This cannot be achieved with a connector having a bearing surface at the free end of the female element.
[0081]
FIG. 3 shows a modification of the connector of FIGS.
[0082]
The connector 15 is shown connected as in a partial axial section. That is, only the part above the axis X2-X2 is shown.
[0083]
Similar to the connector of FIGS. 1 and 2, it consists of a male element 16 and a female element 17, each provided with a single tapered threaded area of a male mold 18 and a female mold 19.
[0084]
The central sealing means 20 is disposed at a region located entirely in the center of the threaded portions of the male mold 18 and the female mold 19, here, at the center position of the length L′ f of the female thread region 19.
[0085]
The stop means that can stop the assembly of the male element 16 to the female element 17 is constituted by an abutment 21 formed by an inner shoulder 22 on the female element, which shoulder faces the axis X2-X2. On top of that, an end 23 of the male element 16 is held, which has a desired shape so that it is held on the shoulder 22.
[0086]
The coupling connector 15 is stopped by the abutment 2 when the desired assembly torque is reached.
[0087]
Obviously, the elements are arranged such that both the threads 18, 19 and the central sealing means 20 provide an interference fit as a result of the existing interference.
[0088]
If necessary, in that case, the male threaded portion 18 is better engaged with the female threaded portion 19, thereby placing the threaded flank opposite the abutment 21 in bearing contact. “Butless” type male and female threads 18 and 19 with flanks can be used.
[0089]
FIG. 4 is a partial sectional view in the axial direction above the axis X3-X3 of another modification of FIGS.
[0090]
In its coupled state, the connector 24 includes a male element 25 and a female element 26, each provided with a single tapered threaded portion of a separate female mold 27 and female mold 28.
[0091]
The central sealing means 29 is provided at a substantially central position along the length L ″ f of the female thread region 28. Like the means of FIG. 1, the means is a male state in which one is mounted on the other in the coupled state. It is constituted by a mold seal surface and a female mold seal surface.
[0092]
In this case, the stopping means capable of stopping the assembly of the male element 25 into the female element 26 at the set position is constituted by the abutment 30 in the same manner as in the example of FIG. The machined convex shoulder 31 serves as a bearing surface for the corresponding concave tapered end 32 of the male element 25.
[0093]
In that example, the abutment 30 has a re-entry taper like an abutment known as a re-entry taper, although the abutment 21 is orthogonal to the axis X2-X2 in the case of FIG.
[0094]
Further, the connector 24 includes second sealing means 33 provided between the inner end 34 of the male mold 27, the end of the female mold 28, and the abutment 30, and the means has a male convex shape. The tapered surface 35 is in intimate bearing contact with the corresponding female concave tapered surface 36 in the coupled state.
[0095]
The central sealing means 29 ensures a seal against the fluid inside the pipe and the fluid outside the pipe, while in some special harsh situations, the central sealing means 29 is used as a seal against the outer fluid. Furthermore, it is important to use the second sealing means 33 as in the example of FIG. In this example, but not limited to the shape of the sealing surface, it ensures a tight seal against the internal fluid.
[0096]
In a variant, the sealing means can be constituted by a sealing ring, for example a sealing device known per se.
[0097]
If the connector has a second sealing means such as 33, it is possible to bias the central sealing means 29 towards the end of the female element.
[0098]
Advantageously, the central sealing means is held within the section AB of the female thread portion having the length L ″ f, where A represents the central position of L ″ f and B is the female element 26. This is a position provided at the center position of half of L ″ f of the free end side strip.
[0099]
As shown in FIG. 3, when the connector is composed solely of central sealing means, the central sealing means 20 is advantageously provided when the means functions as a seal against both external and internal materials. , And placed in the area CD representing 1/4 of the length of L′ f, it is shifted from the center position of the center position C of the female thread portion having the length L′ f. In this case, the shift is toward the free end of the male element 16.
[0100]
In all examples, the central seal passes through the central seal means (20, 29) and is within a cross section orthogonal to the axis, ie, P1-P1 (FIG. 3) or P2-P2 (FIG. 4). At the means level, a sufficient amount of material is reliably supplied to the male (h1m, h2m) and female (h1f, h2f) sides to hold the sealing surface.
[0101]
As a non-limiting method, h1m, h2m, h1f and h2f are kept close to 50% of the thickness of the pipes 3, 4 but can vary to a size between 30% and 80% of their thickness. it can.
[0102]
If the diameter of the inner surface of the male component is made smaller than the diameter of the body of the pipe, for example by making the male end wall conical, the values of h1m and h2m are It can be only slightly larger than 80% of the thickness of the pipe body.
[0103]
5, 6 and 7 are enlarged views of several embodiments of region I of FIG.
[0104]
FIG. 5 shows a tapered male threaded part 7 and a tapered female threaded part 8, which are connected and indicated by their respective teeth.
[0105]
According to a non-limiting example, the thread is a “buttress” type trapezoidal API thread, which is known per se with the load flank of the male mold 34 and female mold 35 and the stub flank of the male mold 36 and female mold 37. It has been.
[0106]
The crest (top) 38 of the tooth of the female screw portion 8 is in a state of interference fit with the bottom surface 39 of the male screw tooth 7 due to mutual interference of the screws, and correspondingly presses the bottom surface of the male screw crest female screw portion. To do.
[0107]
Obviously, differences can be expected between the internal and external thread parts, but they always form an interference fit when assembled.
[0108]
For example, the crest 38 of the female screw portion 8 can form an interference fit with the bottom surface 39 of the male screw tooth 7 by interference of the screw portions while the crest of the male screw portion does not compress the bottom surface of the female screw portion.
[0109]
G1 and G2 represent conical graphic elements, which define the highest spatial requirements of male threaded part 7 and female threaded part 8. The inclination of the graphic element is intentionally exaggerated for easy understanding.
[0110]
Both the external thread part 7 and the internal thread part 8 are interrupted over a set length to form a space for the central sealing means 9. The length can be changed to a length of about 3 to 5 pitches of the threaded portion.
[0111]
The bearing surfaces of the male mold 10 and the female mold 11 forming the sealing means 9 are conical surfaces chamfered parallel to the graphic element G3, and it is advantageous that the slope of the graphic element is higher than the slope of the threaded portion. .
[0112]
The difference α between the slopes of the graphic elements G1, G2 and the slope of the graphic elements of the bearing surface G3 is preferably limited to 20 °.
[0113]
When the connector is assembled, the surfaces 10 and 11 are pressed together by contact pressure to ensure a seal.
[0114]
The contact pressure increases as the degree of interference on the surfaces 10 and 11 increases, and the interference causes elastic deformation that is the source of the pressure.
[0115]
FIG. 5 shows the geometry of the two surfaces 10, 11 before they are assembled in order to represent the actual interference at d1 measured in the direction perpendicular to the connector axis X1-X1. By deliberately showing those aspects. As the degree of interference increases, the contact pressure on those surfaces increases.
[0116]
In the assembled state, when the surfaces are in contact with each other by contact pressure, the contact line is along the graphic element G3.
[0117]
The bearing surfaces 10, 11 are surrounded by clearances 40, 41, which are required upstream and downstream so that the male element can be engaged with the female element and assembled without problems, It becomes unnecessary to use a processing machine.
[0118]
6 and 7 show modifications of the central sealing means 42 and 43. FIG.
[0119]
In FIG. 6, the male bearing surface 44 is constituted by a truncated surface 44, and the graphic element G <b> 4 is parallel to the graphic elements G <b> 1 and G <b> 2 of the screw portions 7 and 8. The female bearing surface 45 is constituted by an annular surface.
[0120]
In FIG. 7, the male bearing surface 46 is annular, and the female bearing surface is truncated by a graphic element G5 parallel to the graphic elements G1 and G2.
[0121]
The interference of the bearing surface is shown in FIGS. At that position they are maximum, i.e. d2, d3, respectively.
[0122]
The bearing surfaces shown in FIGS. 6 and 7 are shown in FIG. In This has the advantage that the surface has an assembly locus shorter than the surfaces 10 and 11 shown. However, the contact pressure distribution formed by the surfaces 44/45 or 46/47 is different from that for the surfaces 10,11.
[0123]
The surfaces of the male and female bearings included in the present invention may have any shape as long as they can press one against the other in a state where the connectors are coupled.
[0124]
Advantageously, the maximum volume of these bearing surfaces is defined by the space that exists between the graphic elements G1 and G2 that defines the space requirement of the thread.
[0125]
In practice, in order to enhance the effectiveness of the inter-bearing of the central sealing means 9, 42, 43 and / or the surfaces 10-11, 44-45, 46-47, a second sealing means such as a connector 33 is further provided. When it is necessary to increase the efficiency of the second sealing means, the crest (crest crest) of one of the screw portions provided on one side of the central sealing means and the root of the screw Can even reduce or even eliminate the radial interference between the two.
[0126]
For that purpose with respect to one of the two elements, namely the male or female element of the connector, up to a distance in the range from 0.005 mm to 0.10 mm measured with respect to the connector axis, the graphic element G1 and The position of G2 can be separated, by processing a part of the graphic element G1 if one functions on the male threaded part, and a part of G2 if it functions on the female threaded part And that part is The left side of the central sealing means is shown in FIGS. 5, 6 and 7 and the right side of the central sealing means is shown in FIGS. This is done by separately processing a part of the graphic element G1 or G2.
[0127]
In such a method, both the part of the graphic element G1 or G2, called the part arranged on the left side of the central sealing means, and the part arranged on the right side are the amount indicated with respect to the connector axis. It remains parallel while being slightly offset in the radial direction.
[0128]
The overall function of the connector which is basically left based on the single female thread area and the single male thread area as described immediately above and further as previously described is changed in all respects in its principle. Rather, the seal feature may be advantageous in each particular situation by radially offsetting one of the threads, i.e. the male or female thread between the sides of the area of the central sealing means. it can.
[0129]
FIGS. 8, 9 and 10 show three examples of coupling types connecting between two pipes. Each uses two connectors of the present invention.
[0130]
FIG. 8 is an axial cross-sectional view through the axis X4-X4 of the connection 48 of the two pipes 49, 50 using the coupling 51.
[0131]
Each pipe 49, 50 connected has a male element 53, 54 at the end.
[0132]
The coupling 51 is provided with a central stop lug 52, and each end of the coupling consists of female elements 55, 56.
[0133]
Each of the respective couplings of elements 53-55 and 54-56 constitutes a connector of the present invention.
[0134]
The male elements 53 and 54 and the female elements 55 and 56 are related to each other so that each configuration corresponds to the above description and each constitutes the present invention. In this case, as shown in FIG. 4, in addition to the central sealing means 57 and 58, each connector comprises a second sealing means of the type described at 33 in FIG.
[0135]
The stop means for stopping the incorporation of the male element into the female element in the set position is here constituted by a stop lug 52 of the coupling 51, which is the same type of abutment as the abutment shown at 30 in FIG. Function as the ment 61, 62.
[0136]
Therefore, the connection according to the present invention is constituted by the two connectors of the present invention.
[0137]
FIG. 9 is a modification of the embodiment of FIG. 8 and shows an axial cross-section along line X5-X5 of the connection of the present invention in which two pipes 63, 64 are coupled by a coupling 65. FIG.
[0138]
In contrast to FIG. 8, the coupling 65 does not include a lug like the stop lug 52 of FIG.
[0139]
In that case, the two connectors of the present invention, constituted by the respective male and female elements 66-67 and 68-69 forming the connection, connect the ends 71, 72 of the male elements 66, 68 to each other. A common abutment 70 formed by bearing contact is included.
[0140]
The common abutment constitutes a common means for these two connectors of the present invention and stops assembly in the set position, whereby the male and female of the central seal means 73, 74 of each connector Match the mold bearing surface perfectly.
[0141]
Furthermore, a second sealing means is provided in the central region 75, 76 of the coupling beyond the screw region of the connector forming the connection. The connection is made in a known manner, for example by means of metal-to-metal bearings of two tapered interference surfaces.
[0142]
In order to accurately place the common abutment 70 in the center position, steps 77 and 78 are performed on the male elements 66 and 68 of each connector forming the connection and further on the female elements 67 and 69. Made in the shape of
[0143]
The axial distance between the female shoulders formed like the coupling 65 is such that when the ends 71, 72 of the male elements 66, 68 are pushing their common abutment 70, their male molds. They are arranged to be slightly smaller than the axial distance between the shoulders so that they do not impede the bearing contact of the ends 71, 72 of the male elements 66, 68.
[0144]
FIG. 9 shows that only one side of step 77 of the male and female shoulders is in contact, and there is a slight axial play on the side of step 78 between the corresponding male and female shoulders. It also shows what to do.
[0145]
The positions of the male and female shoulders of each of steps 77 and 78 are such that the common abutment 70 is located at or near the center of the coupling during assembly, i.e. on the plane of the symmetrical axis Y1-Y1. Arranged to form.
[0146]
FIG. 10 is a modification of the embodiment of FIG. 9 and shows an axial cross-sectional view along X6-X6 of the connection of the present invention in which two pipes 79, 80 are coupled via a coupling 81. FIG.
[0147]
With respect to FIG. 9, each of the two connectors of the present invention, which are constituted by respective male and female elements 82-83 and 84-85 forming a connection, are constituted solely by central sealing means 86, 87. .
[0148]
8 and 9, there is no second sealing means.
[0149]
The connection also consists of a common abutment 89 and steps 90, 91 formed on both the male elements 82, 84 and female elements 83, 85, which elements are symmetric Y2 of the coupling. -Functions to accurately place the abutment 89 in or near the plane of Y2.
[0150]
Desirable axial play is provided so that these steps function in the same manner as described with respect to FIG.
[0151]
In contrast, the central region 88 of the connection does not have a sealing surface and the free region of the central region 88 of the coupling 81 until the unthreaded ends of the male elements 82, 84 collide at the 89 position. Glide with radial play.
[0152]
Obviously, the connection of two assembly type pipes is made by the present invention using the single connector of the present invention.
[0153]
For such a connection, for example, FIGS. 1 and 2 together with FIGS. 3 and 4 should be referred to.
[0154]
In that case, each pipe 3, 4 to be connected holds alternately the male or female element of the present invention at its end, the connection being a male element on one end of the first pipe. 1 is incorporated into the female element 2 at one end of the second pipe 4.
[0155]
As explained above, the connectors of the present invention and the connections made using these connectors are particularly strong and have the desired outer and inner sealing performance.
[0156]
That is, for existing connectors with two radially and axially offset thread regions, the threads are constituted by a single thread region without disrupting the alignment of the taper on which they are formed. It is obtained from the fact that.
[0157]
Furthermore, due to the arrangement of the central sealing means, the complete thread of the threaded portion can extend to two ends when the second sealing means is not provided.
[0158]
That means that the pulling efficiency of the connector is higher than that of a connector of the same size with a sealing surface at the end of the thread.
[0159]
Clearly, the taper of the thread is selected so that the male element can easily engage the female element.
[0160]
Advantageously and in a non-limiting manner, the thread is selected so that the slope relative to the axis is 2.86 ° or greater.
[0161]
The connectors and connections of the present invention are intended to resist high pressures, but are not dedicated to those that typically result from thick, large diameter pipes.
[0162]
Many variations of the present invention can be made. All of them are within the scope of the claims of this application.
[Brief description of the drawings]
FIG. 1 is a partial axial cross-sectional view of male and female elements of a threaded connector of the present invention in an uncoupled state.
FIG. 2 shows the connector of the present invention of FIG. 1 in a state.
FIG. 3 is a partial axial cross-sectional view of the connector of the present invention in a combined state, and the connector is a modification of the connector of FIG. 2;
FIG. 4 is a partial axial cross-sectional view of the connector of the present invention in the assembled state, which is another variation of the connector of FIG.
FIG. 5 is an enlarged view of a portion 1 in FIG. 2 showing a first embodiment of the central sealing means of the connector of the present invention.
FIG. 6 is a modification of FIG. 5 and shows another embodiment of the central seal means of the connector of the present invention.
FIG. 7 is another modification of FIG. 5 and shows still another embodiment of the central seal means of the connector of the present invention.
FIG. 8 is an axial cross-sectional view of a joint of a threaded and coupled connection of the present invention using two threaded connectors of the present invention, the coupling comprising a central stop lug.
FIG. 9 is an axial cross-sectional view of a joint of a threaded and joined connection of the present invention using two threaded connectors of the present invention, the joint having no central stop lug.
FIG. 10 is an axial cross-sectional view of yet another threaded and joined connection joint of the present invention using two threaded connectors of the present invention, the joint having a central stop lug. Absent.

Claims (20)

A male element (1) disposed at the end of the first pipe (3), a female element (2) disposed at the end of the second pipe (4), and a central sealing means (9). The central sealing means is formed by a male bearing surface (10) and a female bearing surface (11), the bearing surfaces being able to press against each other at a connector connection position, wherein the male element (1) Comprising an outer tapered male threaded portion (7), the female element comprising an inner tapered female threaded portion (8) corresponding to the male threaded portion (7), and further comprising stop means (12, 13, 21) a threaded pipe connector that allows the male element (1) to be incorporated into the female element (2) in the connected state so that it can be stopped in a set position. ,
The male threaded portion (7) comprises a male threaded region disposed on a single cone, and the female threaded portion also comprises a female threaded region;
The male and female bearing surfaces of the central sealing means are located in a generally central region of the male thread region for the male bearing surface (10) and the female thread region for the female bearing surface (11). is, the male screw region and the externally threaded portion and internally threaded portion in of the female screw region is suspended, threaded pipe connector.   The connector of claim 1, wherein the male threaded region and the female threaded region include a complete screw and a screw with an incomplete, extinguished or insufficient end.   3. The connector according to claim 1, wherein the central sealing means has a length equal to at most a quarter of the threaded area from the central position of the male threaded area or the female threaded area toward both sides of the central position. A connector that can be placed in an extended area.   The connector according to any one of claims 1 to 3, wherein the stopping means capable of stopping the male element from being incorporated into the female element in the connection state in the set position is directly on the screw portion. A connector constituted by means (12, 13) connected to the.   The connector according to any one of claims 1 to 3, wherein the stopping means capable of stopping the male element from being incorporated into the female element in the connected state in the set position is the screw portion. A connector constructed by another means.   6. The connector according to claim 5, wherein the means different from the threaded portion is an abutment.   The connector according to any one of claims 1 to 6, wherein at least one of the bearing surface, the male bearing surface or the female bearing surface of the central sealing means is constituted by a tapered surface, The taper is in the same direction as the taper of the threaded portion, and the angle of the connector relative to the axis is greater than the angle of the threaded portion taper relative to the axis.   8. The connector according to claim 7, wherein the angle of the tapered bearing surface with respect to the axis of the connector is greater than the angle of the taper of the threaded portion with respect to the axis by a maximum of 20 degrees. 9. The connector according to claim 1, wherein the maximum volume of the male and female bearing surfaces of the central sealing means is between the surface connecting the crest and the surface connecting the valley bottom of each of the male screw portion and the female screw portion. Connector defined by the space present in the. 10. The connector according to claim 1, wherein the male bearing surface and the female bearing surface of the central sealing means have two tapered surfaces , and the taper is greater than the taper of the screw portion. Even high connector. 11. The connector according to claim 1, wherein a valley bottom of the female screw portion or a valley bottom portion of the male screw portion provided on one side of the central seal means is provided on the other side of the central seal means. A connector that is slightly radially away from the connector axis with respect to the crest of the male threaded portion or the crest of the female threaded portion .   12. The connector according to claim 1, further comprising a second sealing means.   13. The connector according to claim 12, wherein the second sealing means includes a male bearing surface provided near a free end of the male element and a female bearing surface provided at a corresponding position of the female element. And wherein the male and female bearing surfaces are in bearing contact with each other during assembly of the connector.   14. The connector according to claim 1, wherein interference between the male and female bearing surfaces of the central sealing means is larger than interference between the male screw portion and the female screw portion. 15. An assembly-type screw connection method for two pipes, formed by a connector according to any of claims 1 to 14, wherein the male element of the connector is formed at the end of a first pipe, the female element Is a connection method formed at the end of the second pipe. In connection method of claim 15, wherein the female element is formed on one end portion of the extension pipe, the connection method the male element is formed at one end of the selectively thicker pipe. 15. A method of connecting two pipes (49, 50) by means of a threaded coupling (51), wherein one male element (53, 54) is formed by the two connectors according to any of the claims 1-14. (49, 50) is formed at each end, female elements (55, 56) are formed at each end of the coupling (51), and one male element of each pipe is one of the couplings. Connection method coupled within each female element at the end. 18. The connection method according to claim 17, wherein in the connected state, the free end of each male element (49, 50) makes bearing contact with the part of the coupling (51) forming the central stop lug (52). the connection method of forming a two abutments (61, 62). 18. The connecting method according to claim 17, wherein in the connected state, the two free ends (71, 72) of the male element (66, 68) make bearing contact with each other, whereby a common abutment (70, 89). Connection method to form). 20. The connecting method according to claim 19, wherein the step of forming a shoulder (77, 78, 90, 91) comprises a male element (66, 68) and a female element (67, 69) close to the central part of the coupling. ) in formed on said common abutment (70,89 by the shoulder) connection method which are precisely positioned.

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